1. Field of the Invention
The present invention relates to a liquid supply apparatus for supplying a liquid such as ink, and a liquid ejection apparatus for ejecting a liquid such as ink.
2. Description of the Related Art
Liquid ejection apparatuses include, for example, an inkjet printing apparatus that ejects ink as liquid from a print head as a liquid ejection head to print an image. In such a printing apparatus, the ink is supplied to the print head from an ink tank (liquid storage section) installed independently of the print head, and when the amount of ink remaining in the ink tank has become zero, the ink tank is replaced with a new one.
U.S. Pat. No. 5,179,389 discloses the structure of using a pressure sensor in contact with ink to detect pressure applied to the ink in such an ink tank for detection of the amount of ink remaining in the ink tank.